Assemblyman Nathan Fletcher, then a Republican, struck a deal last year with Democratic Gov. Jerry Brown on changes to the state’s corporate tax law that would have ended a $1 billion tax loophole for out-of-state companies and then used that new revenue to provide tax breaks for small businesses and the working poor.

Fletcher’s Republican colleagues were stunned. They couldn’t believe he got it done. They congratulated him. Then the Republicans in the state Senate killed it.

Fletcher said they told him: “It’s a good deal, but we can’t let Brown get a win.”

The episode is one Fletcher often recounts on the campaign trail as he tries to burnish the image of coalition builder who is willing to cross party lines to get things done. It was also a contributing factor in his decision to leave the Republican Party in March to run for San Diego mayor as an independent.

Fletcher’s critics, including members of his former party, say his legislative record is indicative of his inability to stick to his principles and shows he’s too quick to compromise on key issues. Some say his voting record is far too liberal for the Republican faithful while Democrats contend he has and continues to be a partisan Republican regardless of his attempt to brand himself independent.

Fletcher said he’ll proudly put his record of accomplishment in Sacramento up against his rivals’ in the mayor’s race.

“I really have, my entire time in office, tried to demonstrate it is possible to hold principled positions and not be polarizing,” he said. “It is possible to actually try and find solutions. It is possible to care more about the strength of an idea than which party it came from. And my legislative career is completely consistent with that approach and I want to bring that same approach to the Mayor’s Office.”

Tony Krvaric, head of the county Republican Party, has been one of Fletcher’s harshest critics, especially after he left the party 18 days after seeking its endorsement. He has accused Fletcher of flip-flopping on issues and called him untrustworthy.

Fletcher is best known for two pieces of legislation he authored: Chelsea’s Law and lifting the downtown redevelopment cap for San Diego.

Chelsea’s Law — named after Poway teenager Chelsea King who was kidnapped, raped and murdered by sex offender John Gardner in February 2010 — enhanced sentencing for predators who commit forcible sex crimes against children, including the “one strike” possibility of life in prison without parole for the most egregious crimes. It also mandates GPS and lifetime parole monitoring and creates zones that prohibit offenders from visiting places where children gather.